Particle Count analysis, as the name implies, counts the number of particles in a given size range in a given volume of sample. We use Laser Light Scattering. This method is capable of counting the number of particles on a given size range. The number of particles and size distributions are then used to determine the Class of Cleanliness. Three different classifications are used throughout the industry: SAE 749D, NAS 1638, or ISO 4406. Each of these classification types has different size groupings and ratings.

Laser Light Scattering
An oscillating laser beam scans a known volume of sample over a given period of time. By measuring the intensity of scattered light and the intensity of incident light in a known period of time, a particle count by micron size can be determined.

Advantages

• The instrument is sensitive to particles down to approximately 4 microns.
  
• Results are easily converted to any of the three standard reporting classifications.

Disadvantages

• The instrument reads even minute air bubbles as particles.
  
• The instrument is sensitive to changes in the oils color.
  
• Large particles may settle out before being counted in low viscosity fluids.
  
• It may be time consuming when analyzing very "dirty" oil.
  

parTicle counting